On Jan 4, 2014, at 4:54 PM, Hitoshi Mitake wrote: > On Sat, Jan 4, 2014 at 11:52 PM, Vyacheslav Dubeyko <sl...@dubeyko.com> wrote: >> >> On Jan 4, 2014, at 4:29 PM, Hitoshi Mitake wrote: >> >>> Current nilfs_check_ondisk_sizes() checks sizes of important structs >>> at run time. The checking should be done at build time. This patch >>> adds a new macro, BUILD_BUG_ON(), for this purpose. It is similar to >>> static_assert() of C++11. If an argument is true, the macro causes a >>> bulid error. >>> >>> Below is an example of BUILD_BUG_ON(). When the checked conditions are >>> true like below: >>> >>> /* intentional change for testing BUILD_BUG_ON() */ >>> >>> static __attribute__((used)) void nilfs_check_ondisk_sizes(void) >>> { >>> BUILD_BUG_ON(sizeof(struct nilfs_inode) > NILFS_MIN_BLOCKSIZE); >> >> So, why do we need to have function for the case of checking on compilation >> phase? > > Just for excluding the checking from other part of code and improve > readability. >
I think that we can have only macro instead of the function nilfs_check_ondisk_sizes(). And this macros can be placed in the begin of main() call. I think that it will be enough for the compilation phase check. >> >> I suppose that we need to have some run-time check anyway. Your approach >> is correct for the current state of the code. But I feel a necessity in >> run-time check >> anyway. Maybe it looks like a paranoia. :) Maybe it needs to extend checking >> in this place. > > Do you mean both of the build time check and the run time check? If > so, I agree with your opinion. I'll send v2 based on this policy. > I mean that block size can be different during volume creation and maybe it makes sense to extend a block size related checking for run-time phase. That's all. But right now I haven't any concrete suggestions. Thanks, Vyacheslav Dubeyko. -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html